Vulnerability Database

328,409

Total vulnerabilities in the database

Validator.isValidSafeHTML is being deprecated and will be deleted from org.owasp.esapi:esapi in 1 year

Impact

The Validator.isValidSafeHTML method can result in false negatives where it reports some input as safe (i.e., returns true), but really isn't, and using that same input as-is can in certain circumstances result in XSS vulnerabilities. Because this method cannot be fixed, it is being deprecated and will be removed in one years time from when this advisory is published. Full details may be found in ESAPI Security Bulletin #12.

Note that all versions of ESAPI, that have this method (which dates back to at least the ESAPI 1.3 release more than 15 years ago) have this issue and it will continue to exist until we remove these two methods in a future ESAPI release.

Patches

There is no patch. We do not believe that it is possible to patch this pretentiously named method other then perhaps renaming it to something like Validator.mightThisBeValidSafeHTML to dissuade developers from using it.

Workarounds

Stop using this method. Note that Validator.getValidSafeHTML is believed to be safe to use with the default antisamy-esapi.xml AntiSamy policy file.

Why is no CVE being filed?

We outline the reasons in the section "Why no CVE for this issue?" in ESAPI Security Bulletin #12. If after reading that, if you still want to file a CVE or this, knock yourself out.

References

CWE-79 CWE-80 ESAPI Security Bulletin #12

No technical information available.

No CWE or OWASP classifications available.

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.